Automatic self-locking expanding mandrel.



S L. GARY & F. B. MOSS. MATIC SELF LOCKING EXPANDING MANDBEL.

AUTO

APPLICATION FILED AUG-21.1917.

Patsnted Man- 4, 1919.

4 SHEETS-SHEET 1.

S. L. GARY 85F. B. MOSS. AUTOMATIC SELF LOCKING EXPANDING MANDREL.

APPLICATION HLED AUG.2l 1917 Patented Mar. 4,1919.

4 SHEI ITS-SHEET 2.

s. L. GARY M. B. MOSS.

AUTOMAHC SELF LOCKING EXPANDlNG-MANDREL.

APPLICATION FILED AUGZM 19!].

Patented Mar. 4:, 1919.

4 SHEETSSHEET 3 7 w 4 a w s. L GARY & F. B. MOSS. AUTOMATIC SELF LOCKINGEXPANDING MANDREL.

APPLICATION FILED AUGJI, 19H.

Patented Mar. 4, 1919.

4 SHEETS-SHEET 4.

' construction of the mandrel in such a man ner that automatic andaccurate centering TED STATES PATENT OFFICE.

SHIRLEY L. GARY AND FRANK B. MOSS, OF RICHMOND, VIRGINIA.

ing Mandrels, of which the following'is a specification.

Our invention relates to new and useful improvements in metal workingtools and more particularly 'to a mandrel for holding bushings and othertubular work while their ends are being trimmed or' their outer facesare being trued, the primary object of our invention residing inthe-provision of an automatic self-locking expanding mandrel which'maybe employed on lathes or other machine.

A still further object of our invention resides in constructing themandrel in such a manner that the work may be readily 'se cured thereonor .freed for removal to insure high eificiency as regards labor saving.

An object which we have in view is the of the work is insured and insuch a manner that any tendency for turning movement of the work aboutthe mandrel will only act to cause a firmer clamping of the work by themandrel.

Another object which we have in'view is the provision of clampingsleeves and supporting rings cooperating with the mandrel proper so thatit may be employed for work of differentlengths and difierent'diameters.

More specifically, our improved mandrel includes a body or chuck portionadapted for attachment to a lathe or other machine and carrying acompound cam member. which cooperateswith a plurality of clampingrollers mounted with respect to the body in such a manner that turningof the hood will cause radial outward swing of the rollers to engagework positioned about the hood.

In this connection a still further object of our invention consists inthe provision of means not only supporting the rollers and governingtheir outward swinging movement but also acting to automatically returnthe rollers to released position when the hood is counter-turned.

Specification of Letters Patent.

carried by a hood rotatablyv AUTOMATIC SELF-LOCKING EXPANDING MANDREL;

Patented Mar. 4, 1919.

Application filed August 21, 1917. Serial No. 187,409.

Still another object resides in constructing the compound cam memberthat sup.- ports the rollers in such amanner'that a relatively slightturning of the hood is all that is required to fully expand the rollers.

rollers and lower roller carrying plate in place,

Fig. 4 is an unassembled perspective view of the main elements of themandrel, illustrating the manner of assemblage,

Fig.5 is a perspective view of a clamping sleeve forming an attachmentfor the mandrel, v Fig. 6 is a perspective view-of a supportlI1% 1lI1%2LlSO forming a mandrel attachment, 1g. 1s a central vertical sectionalview of the chuck wrench employed in operating the mandrel,

Fig. Sis a plan view of the lower roller supporting plate and rollerarms, showing the arms in projected position,

Fig. 9 is a corresponding view showing the arms in retracted position, v

Fig. 10 is a fragmentary sectionalview taken on the line 10-10 of Fig.1, looking in the direction of the arrows. 1

Corresponding and like parts are referred. to in the followingdescription and indicated in all the views of the drawings by the samereference characters.

Our improved mandrel includes a body'or V chuck 10 having asubstantiallycylindrical base portion 11 formed in one end with an axial threadedbore or socket 12 to permit its application to a lathe or other machineand about such end with a thickened hub 13 provided with'radial spannerreceiving portions 14:. The hub portion '11 at its opposite end isformed with an annular "flange 15 and with an axially disposed spindleor shaft16 having a reducedterminal '17 at its free end.

parent and 'a' portion of the peripheral face of the flange 15 adjacentone end of this cutaway portion of the shoulder 1s cut away to providean arcuate seat recelving a rack 22 which in effect/forms a continuationof the flange and which has inclined rack or ratchet teeth 23. Screws 24or other suitable fastening means serve to hold this rack member inplace and the inner face of the rack member may be provided with ashoulder 24 seatin in a channel formed in the body 10 whereby it will beadditionally supported in place. a V

The spindle '16 is formed at spaced intervals with a plurality oflongitudinally extending key-ways 25 opening through its free end, threeof. these key-ways being preferably providedand keys 26 are removablysecured in these key-ways by screws 27', the heads of which arecountersunk in the outer faces of the keys. The free end of the spindleis also formedv with an axial threaded bore 28, for a purpose laterexplained. The construction of this body portion of the mandrel is bestshown in Figs. 1 and 4 of-the drawings. v

Cooperating with the above described chuck or body is a rollercarryinghood, indi: cated as a whole by the numeral 29. This hoodincludes a cylindrical body portion 30 having a top 31 and open at itsbottom. At its bottom this cylindrical body portion 30 is formed with anannular outwardly directed flange 32 provided at its marginal edge withV a depending wall or flange'33 which in turn is'formed with an inwardlydirected flange or shoulder 34 :whereby the flanges 32, 33

and 34 provide an annular chamber. The

top 31 of the hood is formed with a central opening 35 adapted to seatabout the reduced terminal 17 of the spindle, as shown in Fig.

1, and about this opening with a reinforcing bead or shoulder 36: Whenthe hoodis positioned about. the spindle, the inner edge of the flangeor shoulder 34 rests lightly against the peripheral face of the flange15 of the hubv 11 near the lower edge of such flange,

while the inner face of the flange 32 is spaced slightly above the upperface of the flange 15. The wall 30 of the hood is formed with spacedlongitudinal openings 37 ,three of thesebeing preferably provided. Theseopenings extend from the flange 32 to the top 31 and are considerablygreater in width than the width of the remaining portion of the wallbetween themso that the hood in effect forms a sort of cage.

The inner face of the flange 32 is recessed to provide an annular seat38surrou'nd1ng the opening in the bottom of the hood and adapted toreceive a roller supportingring I 39 which is formed with an upwardlydirected annular shoulder 40 projecting through the opening in thebottom of the hood and having its upper face fiush with the upper faceof the flange 32. A plurality of screws 42 or other suitable fasteningmeans serve to hold this ring in place. A plurality of roller supportingarms 43 are pivoted near one end for free swinging movement upon theupper face of the shoulder v40 of the ring 39 by shouldered rivets 44,the arms being identical in shape and size and equally spaced from each.other. hree of these armsare preferably employed and, as shown in Fig. 4and also in Figs. 8 and 9,

they correspond in curvature to the curvathe parts are assembled. Aplurality of cylindrical rollers 48 are formed at their ends withreduced trunnion's 49 to seat in the openings 45 of the upper andlowerroller arms 47 and 43.

Cooperating with these rollers and f i11- closed in the hood and fixedupon the spindle is an expander 50 in the form of a compound cam. Thisexpander includes a cylindrical body portion proper formed with an axialbore 51 channeled to providekey-ways 52 so that the expander may belooked upon the spindle 16. Cam rings 53 and 54 are secured by SC1GWS155to the upper and lower ends of the expander 50 and have their outer orperipheral edges cut away at spared intervals to provide arcuate camfaces which, at their outer ends, merge into the respective peripheraledges and at their inner ends terminate in radial stop shoulders'57, thecam faces 7 being properly spaced and proportioned to be engaged by thepawls or noses terminating at their outer ends in radial stop shoulders59. V

As best shown in Figs. 3, 8 and 9, the rollers engage against thearcuate facesoof engage against the stop shoulders'59, thev noses of theroller carrying arms engage the cam blades 58 and the cam blades are soformed with respect to the cam seats 56 of the rings 53 and .54 thatwhen the rollers the outer portions of the cam seats 56, while .when therollers engage the high portions of the cam faces 59', the noses of thearms carrying the rollers engage against the stop shoulders 57 of thecam seats.

Asa means for turning the hood relative to the spindle, we provide thetop of the hood with a plurality of concentrically disposed upwardlydirected pins 60 adapted to seat in openings 61 of a chuck wrench 62having a cross handle '63. Alocking bolt 64: having a bolt head 65 isthreaded into the bore 28 of the spindle and engages against a washer 66which engages both the reduced shoulder 17 of the spindle and the rib orshoulder 36 of the hood. The

engagement between this latter rib or shoulder 36 and the washer,however, should not be close enough to prevent free turning of the hood.This bolt head 65 is formed with a cylindrical axial extension 67provided at its free end with a conical seat 68in order that it may beengaged with the centering pin of a lathe or other machine, whendesired. The spanner wrench 62 has its base 69 and shank portion 70bored out to provide a chamber 71 to receive th bolt head and washer 66when it is applied to the pins 60.

Obviously, if the rollers are in retracted position, the Wrench may beapplied to the pin 60 and the hood may be turned to cause the rollers toride out over the cam blades 58 of the expander. Of course, reverseturning of the hood will bring the rollers opposite the lower portionsof the cam blades so that they may be retracted. This retraction of therollers is automatic and due to the fact that the noses of the rollersupporting. arms during the counter-turning of the hood ride from thelow to the high portions of the cam faces 56 to swing the free. ends ofthe arms inwardly. This movement of the arms will be readily appreciatedby reference to Figs. 8 and 9 of the drawings.

The normal position of the hood is that in which the arms and rollersare in retracted position, as shown in Fig. 9, and we prefer to providemeans for normally holding the parts in this positlon and for returningthem to such positlon, together with means for locking them in any otheradjusted position. For this purpose, we provide a coil spring 72 whichwe dispose within the annular chamber 20. One end of this spring has adown-bent terminal which seats in any one of aseries of sockets 73formed in the upper face of the flange when desired. Obviously, thetension of this spring-may be Varied by positioning its inner terminalin different sockets 73. This spring is so wound as to normally holdthehood in a certain position which is the position in which the rollerswill engage against the stop shoulders. 59 forming the terminals of theouter ends of the cam blades 58, it being obvious, of course, that thehood could not be turned further in the direction in which the springsisurging it due to such engagement of the rollers and stop shoulders.

As a means for holding the mandrelv n1 locked position, we provide apair of pawls 77 and 78 whichwe mount upon a common pivot pin 79extending through the upper and loweriflanges 32 and 34: of the hoodbase, the. pawls being located within the annular chamber formed betweenthese flanges and the flange 33 being preferably slotted as shown at80to accommodate the intermediate or hub portions ofthe pawls. Springs 81serve to normally urge the active ends of the pawls into engagement withthe ratchet teeth 23 and it should be noted,

that the active terminals of the pawls are spaced one in advance of theother a distance substantially equal to one-half the length of theteeth. By this arrangement, a

much more delicate adjustment is obtained than would otherwise bepossible without making the rack too fine and the pawls too small toinsure eflicient and lasting service. With the pawls mounted andproportioned as described, it will be clear that the hood need be turnedonly through one-half the length of a tooth in order to have it againlocked to the bodyof the machine A pin or shaft 82 is journaled in theupper and lower flanges 32 and 34 and intermediate its length-is a camportion 83 which engages the opposite ends of the pawls 77 and 78 sothat turning of the pin or shaft 82 may swing the pawls out ofengagement with the rack or permit the springs to move them intoengagement, as the case may be. The lower end of the pin or shaftcarries a laterally directed arm or handle 84 by which it may be turned.

In operation, with the mandrel assembled in the manner shown in Fig. 1,the bushing or other tubular work to be operated upon is positionedabout the hood and the rollers carried thereby. The chuck wrench 62 isaction of their springs so that. they may automaticallylock the hood inadjusted position.

- At this point it should be noted, that any tendency of the work toturn about the mandrel will act to cause turning of the" rollers such aswould roll them farther outupon'the cam blades so that any such turningwill only act to move-the rollers into closer engagement with the workand cause the man drel tomore firmly grip the work;

In order to release the work from the mandrel, it is only necessary toswing the handle 84 of the shaft 82 to lock the pawls in inactive;position, when the spring 7 2 will immediately return the hood to normalposition, automatically retracting the rollers and freeing 'theworkwhich may then be lifted from the mandrel.

In some instances, the diameter of the work -may be "too large for theparticular mandrel to be employed and for this reason we preferablyprovide each mandrel with an attachment in the form of'split resilientsleeves, such as that shown at 85 in Fig. 5. These sleeves should be ofa diameter to be engaged by the mandrel and of varying thicknesses sothat 'whenfthey' are sprung open upon being engaged upon the mandrelthey may be forced into engagement with workof varying internaldiameters. To insure sufficient resiliency,the outer faces of thesesleeves are preferably castle-cut or channeled longitudinally at spacedintervals, as shown at 86. V

Our improved mandrel is particularly adapted for use in holdingbushings, etc., while their ends are being trued or cut-off and in orderto prevent injury to the mandrel, the end of the work should projectbeyond the outer ends of the rollers. In order to insure this, weprovide another attachmentconsisting of a series of supporting ringssuch as that shown at 87in Fig. 6, of varying thicknesses adapted to beseated upon. the flange 32 of the hood and having centering pins 88projecting from their lower faces which are adapted to sea-tin openings89 formed in the fiange 32; I

From the foregoing description, it will be apparent that our improvedmandrel is practically automatic in its'action, as a slight turn of thewrench 62 is all that is necessary to secure the work in place, while amere swing of the handle 84: 'is' sufficient to cause 66 release of thework. Because of this, rapid andaccurate application of the work to themandrel maybe made and a great saving in time may be had. At the'sametime, there are no delicate parts to become injured or worn through useand all parts are readily.

accessible in case repairs are necessary. Furthermore, all duplicateparts, such as'the rollers, roller supporting arms,'cam-r1ngs '53 foundadvantageous either in structure orin proportion or arrangement ofparts, may j be madeprovidin'g' they fall within of the claims; a

Having thus descrbed the invention, what is claimed as new is:

' 1. An expanding mandrel comprising a body, a hood mounted thereon andmovable relative thereto, clamping elements carried by the hood, meanswhereby movement of the hood will proj eet or retract the clampingelements, means for locking the clampingelements'in an adjustedposition, and yieldable means tending constantly to hold the clamp ingelements retracted. V

2. An ekpansible mandrel comprising a body, a hood mounted thereon andturnable about the same, work-engaging elements mounted in the hood andmovable to projecttherefrom or be housed therein, means whereby turningof the hood will cause the said elements to be projected or retracted,

means on the hood and the body to'loek the the scope 1 hood againstturning from a set position,

and means acting on the body and the hood to hold the hood constantly innormal position with the work-engaging elements retracted.

' 3. An expanding mandrel including a body formed with a spindle, keysengaging the spindle, a compound" cam member mounted about thespindleand locked thereto by. the keys, radially curved cam blades carried bythe=cam member, a 'hoodmounted for turning movement about the cammember, swngingly mounted arms' carried "by.

the hood, rollers journaled infthe arms and engaging the arcuate camfaces whereby turning of the hood with respect to the cam member willcause projection of the rollers, and means cooperating between the armsand the compound cam member whereby counterturning of the hood willcause retraction of the-rollers. V r r .4. An expanding mandrelincluding a body formed with .a spindle, keys engaging the spindle, acompound cam member mounted about the spindle-and locked there' to bythe keys, radially curved cam blades carried by the cam member, a hoodmounted for turning movement about the cam member, swingingly mountedarms carried by the hood, rollers journaled in the arms and'engaging thearcuate cam faces whereby turning of the hood with respect to the cammember will cause projection of the rollers, and means cooperatingbetweenthe arms and the compound cam member whereby counter-turning ofthe hood will cause retraction of the rollers, said means including camseats at the ends of the cam member cooperating with the arms to causeswinging of the arms during turning of the hood.

5. An expanding mandrel including a supporting body, a hood mountedonthe body, rollers carried by the hood and movable toward and away fromthe body, means for moving the rollers toward and from the body as thehood is rotated about the body, and interengaging means on the hood andthe body for locking the rollers in any adjusted Position.

6. An expanding mandrel including a spindle, a member fixed to thespindle and having radially curved longitudinally extending cam blades,rings secured to the ends of the member and formed with correspondingcam seats, a hood surrounding such member, a plurality of arms pivotedto the hood adjacent its ends and having pawl portions engaging the camseats, and roll- .ers journaled in the arms and engaging the cam bladeswhereby turning of the hood relative to the spindle and member mountedthereon will act through the engagement of the rollers with the camblades and of the arms with the cam seats to project and retract therollers through swinging of the arms.

7. An expanding mandrel including a spindle, a member fixed to thespindle and having radially curved longitudinally extending cam blades,rings secured to the ends of the member and formed with correspondmg camseats, a hood surrounding such member, a plurality of arms pivoted tothe hood adjacent its ends and having pawl portions engaging the camseats, rollers journaled in the arms and engaging the cam blades wherebyturning of the hood relative to the spindle and member mounted thereonwill act through the engagement of the rollers with the cam blades andof the arms with the cam seats to project and retract the rollersthrough swinging of the arms, and means normally tending to hold thehood in a predetermined position relative to the spindle and toautomatically return it to such position when moved to another position.

8. An expanding mandrel including a spindle, a member fixed to thespindle and having radially curved longitudinally extending cam blades,rings secured to-the ends of the member and formed with correspondingcam seats, a hood surrounding. such member, a plurality of arms pivotedtothe,

hood adjacent its ends 'and having "pawl portions engaging the camseats, rollers journaled in the arms and engaging the cam blades wherebyturning of the hood relative to th espindle and membermounted thereonwill act through the engagement of the roll ers with the cam blades andof the arms with the cam seats to project and retract the rollersthrough swinging of the arms, 7

means normally'tending to hold the hood in a predetermined positionrelative to the spindle and to automatically return it to such positionwhen moved to another position, and means for locking the hood againstsuch return movement.

9. An expanding mandrel including a body, a hood'mounted for turningmovement about the body, clamping elements,

means operable upon turning of the hood for projecting and retractingthe clamping ele- 10. An expanding mandrel including a body. a hoodmounted for turning movement about the body. clamping elements. meansoperable upon turning of the hood for projecting and retracting theclamping elements through the hood. a spring normally tending to holdthe hood in a predetermined position with respect to the body, aplurality of ratchet teeth formed upon the body, spring pressed pawlscarried by the hood and engaging the teeth. and means for swinging thepawls out of engagement with, the teeth. one pawl projecting in advanceof the other a space equal to substantially one-half the length of atooth whereby turning of the hood with respect to the body through adistance equal to onehalf the length of a tooth where one pawl wasacting will render such pawl inactive and the other pawl active.

11.An expanding mandrel. comprising a body, a compound cam about thebody. a hood rotatably mounted on the body. ivotally mounted armscarried by the hood. and rollers supported by said arms and extendinglongitudinally of the hood. said arms and rollers bearing upon. the camwhereby rotation of the hood will project or retract the rollers.

12. An expanding mandrel comprising a body, a compound cam about thebody, a

hood rotatably mounted on the body, pivotally mounted arms carried bythe hood,

rollers supported by said arms and extending longitudinally of the hood,said arms and rollers bearing upon the cam whereby rotation of the hoodWill project or retract the rollers and means housed between the hoodand the body tending constantly to rotate the hood in onedirection'whereby the rollers will be held normally retracted. 10

In testimony whereof We affiX our signatures. 1 V

SHIRLEY L. GARY.- [1,. s] FRANK B. MOSS. 1[L. 8.]

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

Wa'shingtonfl). C.

